Mandrel for casting chilled pipes



(No Model.)

W. G. WESTAWAY. MANDREL FOR CASTING GHILLED PIPES.

No. 465,035. Patented Dec. 15,1891.

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UNITED STATES PATENT OFFICE.

\VALTER C. \VESTA\VAY, OF DEGORAH, IO\VA.

MANDREL FOR CASTlNG CHILLED PIPES.

SPECIFICATION forming part of Letters Patent No. 465,035, dated December15, 1891. Application filed February 19,1891. Serial No. 382,128. (Nomodel.)

To all whom it may concern.-

Be it known that I, WALTE (J; WEs'rAwAY, a citizen of the United Statesof America, residing at Decorah, in the county of I'Vinneshiek, in theState of Iowa, have invented certain new and useful Improvements inMandrels for Casting Chilled Pipes, of which the following is aspecification.

Referring to the accompanying drawings, wherein like reference-lettersindicate like parts, Figure 1 is a side elevation, and .Fig. 2 a sectionin line 2 2 of Fig. 1.

For many purposes in theindustrial arts it is desirable to use metalpipes of smooth cylindrical or substantially cylindrical bore, chilledon the inside. To cast such a pipe, it is necessary to cast the metalaround a cent-ral mandrel or chill. It has, however, been found inpractice that the contraction of the chilling metal against the mandrelstrains the walls of the pipe, and the mandrel then expands by the heatcommunicated to it from the pipe, increasing the strain to such anextent as often to burst the pipe and always to render it weak andpractically worthless unless cast very thick and heavy, and it isdifficult to remove the mandrel from the pipe after the casting has beenmade.

The object of my invention is to so improve the construction andoperation of the mandrel or chill as to obviate the difficultiesreferred to and the invention consists in the improved mandrel or chillherein described.

In the drawings, Aindicates a hollow mandrel, with its bore 13 somewhateccentric to its periphery, and having from end to end at its thinnerside a longitudinal division or opening, tapering outward incross-section, and filled up when in use with a strip or key 0, ofcorresponding form. In preparing the mandrel for use the key 0 isinserted and held in place by anysuit-able elastic or yieldingmaterial-for example, by sand tamped in the bore of the mandrel, asindicated in Fig. .3. IVith such a mandrel the contracting metalchilling around it forces the wedgeshaped key slightly inward againstthe resistance of the material in the bore, and at the same time bycompressing the walls A it springs or bends them inward at their dividedside tightly against the key, the eccentric bore causing the flexure todistribute itself with substantial uniformity throughout the entireperiphery of the wall A, and thus preserve the cylindrical form of thecasting. l/Vhen the casting is completed, the sand is removed, the keydislodged inwardly, and the mandrel is then readily loosened anddetached from the pipe. Instead of the metal key, the sand itself may beused as a key by tampi ng it tightly into the dividing-space andsmoothing and polishing the outer surface, in which case thedividing-space need not necessarily be made wedge shapein crosssection.

By the word pipes as used herein I mean any tubular form, long or short,including wheel-hubs, journal-boxes, and similar articles, as well asthe articles commercially known as pipes.

I find it easy,with mandrels or chills of the kind above described, tocast metal pipes of extreme thinness, and yet of great strength, withtheir inner surfaces chilled, smooth, and cylindrical, requiring nofurther finish for ordinary uses, and with their outer surfacesunchilled and of great tensile strength. The interior surface of thepipe takes its form instantly upon the first contact of the hot metalwith the cold mandrel, and the latter the-n supports it sufficiently toprevent any alteration of such form, although yielding inwardlysufliciently to prevent its own expansion from uudulystraining thesurrounding plpe.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The improved mandrel or chill for easting purposes herein described,consisting of an eccentrically-borcd metal tube divided longitudinallyat one side, with a metallic key interposed in the dividing-space, andwith the center provided with a yielding material to hold the key inposition, substantially as herein set forth.

2. The improved mandrel or chill for casting purposes herein described,consisting of an eccentrically-bored tube divided by a longitudinal slotat the thinner side, and a filling for said bore and slot arranged toyield as the casting cools, substantially as described.

3. The improved mandrel or thill for east- 5 ing purposes hereindescribed, consisting of an eccentricall'y-bored tube divided byalongitudinal slot widening toward the center of the tube, a key fittingsaid slot and havinga broad head bearing against the edges of the innersurface of the tube, and a yielding fill- [0 ing for the bore to holdsaid key in place, substantially as described.

WVALTER (l WESTAWVAY. WVitnesses:

W. M. HILL, FRANCIS E. DRESSER.

